What is the island formed from the accumulation of coral?

The island formed from the accumulation of coral is known as a "coral atoll." These atolls typically develop around a submerged volcanic island, where coral reefs grow in a circular pattern, creating a lagoon in the center. Over time, as the volcanic island erodes and sinks, the coral continues to thrive and build up, eventually forming a landmass that can support various ecosystems. Coral atolls are commonly found in tropical and subtropical ocean waters.